The nation's highways provide a means whereby millions of trucks-trailer transports and the like are freight carriers and move a majority of cargo and commodities from one point to another.
There is no suitable device installed over or around the wheels of these transports to prevent the generation and dispersement of finely divided water streams or snow mists during a storm, which in turn are thrown sideways into the path and windshields of vehicles using the passing lane (or vehicles being passed). As a result thousands of highway deaths occur each year and unlimited risks are taken by these motorists to themselves as well as others in the immediate vicinity. (Highway safety reports 40,000 deaths occur each year).
The present invention is directed to a fender design which serves multiple purposes. One object is to cool the tires and brake assemblies. When the carriers are not traveling under rainy conditions and are traveling in warm to hot climates, the tires tend to heat excessively, resulting in reduced tire life. For example, if ambient temperature is 95.degree. F., the temperature of the tire can be as high as 160.degree. F. Further, under these conditions, the brake assemblies are also at a relatively higher elevated temperature and do not function as effectively as they would at ambient temperature. Accordingly, the present invention embodies a fender design which cools the tires and brake assemblies when the tires are operating at relatively hot ambient temperatures.
Another object is to reduce or eliminate the spray generated by the rotating tires under wet conditions.
It is believed that the closest prior art is best exemplified by my earlier issued U.S. Pat. Nos. 4,858,941 issued Aug. 22, 1989 and 5,100,177 issued Mar. 31, 1992. These patents teach fender designs which partially encase the rotating wheels of a moving vehicle and comprise a front plate with openings and/or a top plate and/or a back plate having either openings or vanes and optionally a side plate having louvered openings. Also relevant is Italian Patent 473134 which teaches louvered openings on a fender wall.
In the design of my original fenders, the primary intent was to prevent or inhibit the spray which would be cast up and laterally outward by the rotating wheels when traveling under rainy conditions. A subsidiary aim or objective of the prior fenders was to cool the tires and brake assemblies areas to enhance the life of the tires and brake assemblies.
Although my prior designs were generally satisfactory for the then intended primary objective, namely reducing or eliminating spray, they were not fully effective for either controlling the spray or for cooling the rotating tire and brake assembly.
With my prior fender designs, it was found that under certain road conditions, namely moderate to heavy rains and low to moderate speeds, that the force of the water spray centrifugally cast from the front upper quadrant of the rotating tire was so great that it was cast through the openings in the forward portion of the fender with the result that the spray was not minimized or inhibited as expected.
Further, it was found that only the forward portion of the fender was fully effective in both cooling the forward portions of the tire and brake assembly. Analysis of the fluid flow characteristics of the air flow within the control zone defined by the fender confirmed that there was little or no effective cooling action on the rearward portion of the tire or brake assembly. By control zone is meant the area defined by the inner surface of the fender and the portion of the rotating tire within the fender and the outer surface of the brake assembly.
One aspect of the invention embodies a leading section of a fender which includes parabolic-like-shaped blades to ensure that the air flow into the upper leading quadrant of the rotating tire is sufficient to control the spray and to cool the tire and brake assembly. Further, the blades are designed to entrap spray cast forwardly from the rotating tire by centrifugal force and to redirect that spray downwardly. In this aspect of my invention, the blades control the air flow and collect and control the spray contacting the inner surface of the blades. Each of the blades has a leading edge and curved upper and lower outer surfaces. The opposed surfaces of adjacent blades define a flow path which ensures that the velocity of the air flowing therethrough is greater than the force of the spray cast from the rotating tire. The spray cast from the rotating tire is not cast through the openings under normal operating conditions. The concave inner surface of the blade terminates in a baffle. The spray cast onto the inner surface coalesces, is sheeted off the edge of the baffle and ultimately is discharged inwardly and downwardly from the fender.
In another aspect of the invention, an enlarged scoop section is formed on the upper leading portion of the leading section of the fender. In a preferred embodiment, with a pair of fenders, this scoop portion can be used on one or both fenders.
In still another aspect of the invention, an apertured side wall is secured to the leading section or to the wall of a moving van. The side wall is designed to ensure that substantially the upper half of the tire and brake assembly is uniformly contacted by cooling air streams. The side wall is characterized by slot-like apertures which are specifically proportioned to ensure uniform air distribution within a control zone. This results in longer tire life and longer life for brake assemblies. Further, it also results in much more efficient control of the spray cast by the rotating wheels than with my prior designs.
Tractor trailers, including the spatial relationship between the wheels and the carriages which they support, assume many configurations. There are what is referred to a dry box trailers (vans) which when loaded the carriage may only be 3 to 4 inches above the top of the rotating tires. There are flat bed trailers where there is usually a substantial clearance between the top of the tire and the underside of the carriage even when fully loaded. There are moving vans (trailers) where typically the tire rotates within a wheel well formed within the carriage of the van or busses. There are also trailers which are in essence tanks supported on a carrier for transporting gas, oil, etc. Because of all these various configurations, one or all aspects of my invention may be used in combination with any of these trailers. That is, embodiments of only the leading section, the leading section and the side wall, the side wall (i.e. the wheel well of a bus), the side wall, a side wall and a trailing section in combination can be used alone or in combination with or without a top which top in and of itself may or may not have an air scoop formed therein.